But the two runs had to occur within an hour of each other to set a record, and the second run missed that window by a minute.

Green, 35, achieved the milestone on the eve of the 50th
anniversary of the first supersonic flight, by American test
pilot Chuck Yeager on October 14, 1947.

Green and team leader Richard Noble have worked for years to
crack the sound barrier with a car on land, and in recent
weeks they intensified their quest.

The sound barrier, which varies according to altitude and
temperature, is currently 755 mph on the Black Rock Desert.
Green set the previous world speed record for a car on
September 25 when he took Thrust up to 714 miles per hour.

On Sunday, the "Spirit of America" team led by Craig
Breedlove made a test run of 517 miles per hour following a
531 mph run on Saturday. It's not clear what's next, if
anything, for the Americans.